SYSTEMS AND METHODS FOR MESSAGE AUTHENTICATION USING EFFICIENT SIGNATURES AND SECRET SHARING

A method for message authentication includes computing a first secret data and a second secret data using a signing key associated with a first communication message. The method includes splitting the first secret data and the second secret data into shares among a plurality of key holders n for storage at the plurality of key holders n. The method includes receiving a reconstruction request to compute a hash-based message authentication code (HMAC) signature for the first communication message employing the shares from at least t≤n of the plurality of key holders n to compute the signature with a Secure Multi-party Computation (SMC) protocol. Further the method includes computing the signature using the shares from the at least t≤n of the plurality of key holders n as inputs to the SMC protocol in place of the signing key.